I'm a web developer in Norfolk. This is my blog...

Passcrunch

As an exercise to teach myself the basics of regular expressions in JavaScript I decided to implement a small function I called passCrunch to check how secure a password is. I implemented it based on the following principles:

First of all, check for a list of well-known easy to break passwords to foil a dictionary attack, and reject it if it’s there.

Then check that it’s at least 8 characters, and reject it if it’s not.

Then implement a counter to measure how secure it is by various checks.

Then add to the rating if it’s more than 12 characters.

Add to the rating if it contains lowercase letters.

Add to the rating if it contains uppercase letters.

Add to the rating if it contains numbers.

Add to the rating if it contains nonalphanumeric characters.

Finally, convert the result to a percentage score and return it as an integer.

The finished article’s available here as a .zip file if you’d like to use it, or just take a look at the code. Be warned, it’s quite long due to the fact that the list of insecure passwords I used had in excess of 3,000 entries in it! It includes a very simple HTML form which will allow you to submit a function and will return a score for it via an alert() dialogue. Feel free to use it if you wish!

About me

I'm a web and mobile app developer based in Norfolk. My skillset includes Python, PHP and Javascript, and I have extensive experience working with CodeIgniter, Laravel, Django, Phonegap and Angular.js.